Conductive adhesives made of an adhesive resin composition containing conductive fillers therein have been used to attach a reinforcing plate or an electromagnetic-wave shielding film to a printed wiring board. To attach the reinforcing plate or the electromagnetic-wave shielding film to the printed wiring board, an opening is formed in a cover lay of the printed wiring board to expose a circuit made of, e.g., copper foil, and the opening is filled with a conductive adhesive so that the circuit and the reinforcing plate or the electromagnetic-wave shielding film are electrically connected to each other.
An adhesive made of a thermosetting resin to which conductive fillers and silica particles having a given specific surface area have been added is disclosed as an example of such a conductive adhesive. It is disclosed that the addition of such silica particles contributes to reducing damage to an insulating layer without reducing the flexibility of the electromagnetic-wave shielding film as a whole (see, e.g., PATENT DOCUMENT 1). An adhesive sheet made of an adhesive composition containing polyurethane polyurea resin having a predetermined acid value and epoxy resin is also disclosed. It is disclosed that using such an adhesive sheet contributes to an improvement in reflow resistance (see, e.g., PATENT DOCUMENT 2).